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Rendering with Arnold in Houdini and Solaris using the HtoA plug-in.
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Arnold GPU just creates a grey frame with Arnold

Message 1 of 8
780 Views, 7 Replies

Arnold GPU just creates a grey frame with Arnold

I updated arnold to Htoa to take advantage of the light linking now supported in Arnold GPU. This meant i Had to also change houdini build from 18.0.566 to 18.0.597. Unfortunately GPU rendering has stopped working altogether. Scenes that were working fine now just present a solid grey render buffer in the render view. I looked at the console and it says WARNING [htoa node] [soho] Parameter not found: radius (ar_radius)

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Message 2 of 8

Can you increase the Arnold log verbosity to Detailed, and post that log?

I don't think that WARNING would explain a solid grey render buffer.

// Stephen Blair
// Arnold Renderer Support
Message 3 of 8

Hi @Stephen Blair, That's kinda what i suspected. Here is a link to the log file:

Download link

This website does not allow a direct upload of the log file unfortunately

Message 4 of 8

@Adam Phillips

That's a strange log. It never actually renders, and it just re-exports the temporary ass file that was supposed to be rendered.

Does this work on CPU?

What if you Ignore Textures (in the Arnold ROP > Diagnostics) ?

// Stephen Blair
// Arnold Renderer Support
Message 5 of 8

Hi @Stephen Blair, Exactly! it just makes a solid grey render buffer - the 'Generating Image' kind you'd get whilst waiting for first pixel and then stops.

CPU works fine - it's been a lifeline. It's not like the scene is huge either - literally one asset (750k polys) one set of maps and one shader with some very basic shadow/phantom geometry.....that's it. I'm also running an RTX 3090 which should be overkill for a project like this.

The only thing I can think to do is totally uninstalling all aspects of houdini/Arnold when the project is over and starting again.

ignore textures does nothing, same with ignore lights,bump,shaders etc....

Message 6 of 8


Does rendering to MPlay work with GPU? And rendering to disk?

// Stephen Blair
// Arnold Renderer Support
Message 7 of 8

Hi @Stephen Blair , Rendering to disk seems to be working. preview in Mplay doesn't work, there is no response in Mplay window. Judging by my computer fans the same thing is happening.

Message 8 of 8

aaannnnddd just like that it starts to work. I have changed 0 settings - perhaps the render to disk or Mplay attempt jogged something

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